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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Alexey Sheplyakov <asheplyakov@basealt.ru>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.19 024/155] xhci: Fix null pointer dereference in remove if xHC has only one roothub
Date:   Tue,  6 Sep 2022 15:29:32 +0200
Message-Id: <20220906132830.449841834@linuxfoundation.org>
In-Reply-To: <20220906132829.417117002@linuxfoundation.org>
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From: Mathias Nyman <mathias.nyman@linux.intel.com>

[ Upstream commit 4a593a62a9e3a25ab4bc37f612e4edec144f7f43 ]

The remove path in xhci platform driver tries to remove and put both main
and shared hcds even if only a main hcd exists (one roothub)

This causes a null pointer dereference in reboot for those controllers.

Check that the shared_hcd exists before trying to remove it.

Fixes: e0fe986972f5 ("usb: host: xhci-plat: prepare operation w/o shared hcd")
Reported-by: Alexey Sheplyakov <asheplyakov@basealt.ru>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220825150840.132216-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/host/xhci-plat.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 044855818cb11..a8641b6536eea 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -398,12 +398,17 @@ static int xhci_plat_remove(struct platform_device *dev)
 	pm_runtime_get_sync(&dev->dev);
 	xhci->xhc_state |= XHCI_STATE_REMOVING;
 
-	usb_remove_hcd(shared_hcd);
-	xhci->shared_hcd = NULL;
+	if (shared_hcd) {
+		usb_remove_hcd(shared_hcd);
+		xhci->shared_hcd = NULL;
+	}
+
 	usb_phy_shutdown(hcd->usb_phy);
 
 	usb_remove_hcd(hcd);
-	usb_put_hcd(shared_hcd);
+
+	if (shared_hcd)
+		usb_put_hcd(shared_hcd);
 
 	clk_disable_unprepare(clk);
 	clk_disable_unprepare(reg_clk);
-- 
2.35.1